Just started it and never realised how great it actually is for balance! Plus if you sway over, you can just pretend it was part of your personal interpretation of the dance routine
I do a lot of trail running and have been practicing yoga for several years and love it, but with bellydance I found a very different way of working out the body, which complements the other two. I found that dancing is great as the whole body moves freely (depending on which type of dance of course), loosening everything up while strengthening it at the same time!
I heard that Tai Chi is also fantastic for balance (and a lot less risky injury-wise if falling over I guess!).